Reassembled and ready, Solar Impulse 2 stands ready to leave Abu Dhabi on an historic around-the-world flight within the next month, according to the project’s latest announcements. When HB-SIB leaves Abu Dhabi, it will cross two oceans and four continents before returning to its departure point. The trip will include landings in 12 locations and a total distance of 35,000 kilometers (21,700 miles) – all without using a drop of fuel. Its route and schedule will be affected by weather, and since the airplane will fly at only 27 miles per hour at night to conserve battery energy, by prevailing winds. Normal flight speeds will range from 50 to 100 kilometers per hour (31 to 62 mph). The press release …

The first Solar Impulse airplane, HB-SIA, has demonstrated repeatedly that it can stay up all day and all night. The idea of perpetual flight has enticed designers for years, but the idea of a perpetual pilot has not – until the space age. Charles Lindbergh had a restless night before his May 20, 1927 takeoff for Europe and spent much of the 33-1/2 hour flight battling his nearly overwhelming need for sleep. A solar-powered flight will be considerably slower, and thus longer in duration, than Lindbergh’s epic voyage, however. With planned flights for HB-SIB, the second Solar Impulse craft, anticipated to span continents and oceans, the need for maintaining pilot health and alertness becomes imperative. As the team explains, “Over …